Method and apparatus for texturing thermoplastic yarn



Jan. 23, 1968 E. K. MCINTOSH ETAL 3,364,540

METHOD AND APPARATUS FOR TEXTURING THERMOPLASTIC YARN Filed Aug. 5, 1964 INVENTORS E. K. Mc/NTOSH J. R. WILLIAMS ATTORNEY United States Patent 3,364,541) METH IGD AND APPARATUS FUR TEXTURING 'IHlERhtlGELAdTfQ YARN Euell K. McIntosh, Pensacola, Fla, and James R. Williams, Rohertsdale, Alan, assignors to Monsanto Company, a corporation of Delaware Filed Aug. 3, 1964, Ser. No. 386,376 9 Qlairns. (ill. 28-457) ABSTRACT 015 THE DIESCLUSURE A thermoplastic yarn can be advantageously textured by passing the yarn under tension into contact with the periphery of a plurality of axially parallel, unidirectionally rotating heated surfaces with the axis of the yarn parallel to the rotational axes of the heated surfaces.

This invention relates to the texturing of yarn made from a thermoplastic polymer. More particularly, it re lates to the production of a thermoplastic yarn having a deformed surface employing unique apparatus for producing the deformation.

Continuous thermoplastic yarns, especially nylon yarns, have properties, such as strength and durability, that make them commercially attractive. Neverth less, continuous thermoplastic yarns are in some ways undesirable. Untextured yarn is often difficult to process. Furthermore, many times untextured thermoplastic yarn is undesirably lustrous. To overcome these and other problems various texturing methods have been developed. The present invention is a new and attractive advance in such texturing methods.

An object of this invention is to provide a method for deforming the surface of thermoplastic yarn.

A further object is to provide apparatus for efficiently deforming the surface of warn made from thermoplastic polymer.

Other objects will be apparent from the following descriptive material.

The objects of the invention are achieved in the provision of a texturing method whereby yarn under tension is passed in contact with the periphery of a plurality of axially parallel, thin, unidirectionally rotating surfaces, thus deforming the yarn surface. Apparatus for performing the method comprises a plurality of overlapping, adjacent, axially parallel, unidirectionally rotatable discs. Moving thermoplastic yarn under tension is contacted with the periphery of the above mentioned discs, the axis of the yarn being substantially parallel to the axes of rotation of the discs. The yarn is either softened or soft when it comes into contact with the discs. Softening is achieved in one of three ways: the yarn is softened by friction heat as it rubs the periphery of the discs, it is softened by the discs themselves which are heated, or solvent is applied to the yarn prior to its contacting the discs. As the moving yarn passes over the periphery of the rotating discs, it is scuffed and otherwise deformed, thus producing yarn having reduced luster and other attractive features.

In the drawing:

FIGURE 1 is a perspective, schematic view generally showing the invention.

FIGURE 2 is a plan view of the apparatus of the invention.

FIGURE 3 is a broken out elevation view of the discs in the act of processing yarn.

FIGURE 4 is a sectional view of the apparatus in accordance with section line l-4 shown in FIGURE 2.

The invention will now be described in detail with specific reference to the drawing. As shown in FIGURE 3,3645% Patented Jan. 23, 1%68 1, yarn It is taken from spin cake 12, passed around snubber guide 14 and into contact with feed rolls in. The yarn then passes around draw pin 18. From draw pin 13 the yarn is wrapped three times around draw roll 20 and separator roll 22. After these three wraps, the yarn passes over guide 2 and down through solvent applicator 25 (whose function and effect will be described later) into contact with the periphery of the unidirectionally rotating discs in disc assembly 26. The axis of the yarn is substantially parallel to the axes of the discs. By reference to FIGURE 2, one can see the position yarn It] takes in relationship to discs 36 and 32%. From disc assembly 26 yarn passes through guide 28 to draw roll 20 and separator roll 22. After twice passing around rolls Ztl and 22, the yarn moves through guide 3% and is then taken up in an orderly manner by take up 32.

To describe the method whereby the yarn is deformed, FIGURES 2 and 3 will be hereinafter referred to. It must be kept in mind that the direction of rotation of both discs is the same. For purposes of description the disc rotational direction will be assumed to be clockwise. As can clearly be seen from FIGURE 2, when the disc rotational direction is clockwise, disc 38 will tend to pull the yarn toward the junction, while disc 36 pulls the yarn away from the junction. By the action of these two forces yarn M will be rotated counterclockwise. As one can see from FIGURES 2 and 3 the discs overlap 'but do not touch. Therefore, as a certain, predetermined point on the threadline touches the upper disc, it is scuffed and rotated counterclockwise. Before the predetermined point reaches the second disc it has been rotated in a counterclockwise direction to some degree. Thus, when the predetermined point passes the second disc 28 the yarn is scuffed at greater than away from the first contact point rather than, as it would appear on first glance at the drawing, about 90 away from the first point. However, the yarn tends to rotate to a certain degree and then to spring back to its original position. As this action is repeated the scuifs on the yarn take on a rather helical configuration.

To achieve proper scufiing action, the yarn must be softened. One method of softening is to apply solvent from solvent applicator 25 shown in FIGURE 1. Among the suitable nylon solvents are chloral hydrate and resorcinol. A second method is to bring the yarn into force contact with the discs so that friction heat is generated to a degree sulficient to soften the surface of the yarn. The third method is the heating of the discs with external heat. This is the preferable method. The discs in this last method are heated to between and 250 C. The method of determining temperature will be hereinafter discussed more fully.

Various disc configurations yield different yarn disfigurations. A knife-edged disc not only scuffs the yarn but also scrapes up small fibrils that are attached at one end to the main trunk of the yarn. A rounded edge generally only sculfs the yarn. Yarn textured with sharpedged discs is delustered and has greater cover than nontextured yarn. Yarn textured with rounded edge discs is substantially delustered with some improvement in hand.

The invention may be practiced on multifilament yarn as well as monoiilarnent. However, when the filament number is larger than about three, the yarn produced is not scuffed and otherwise textured to as marked a degree as when the yarn bundle has less than about three filaments.

It must be noted that the string up shown in FIGURE 1 is not the only string up possible in this invention. The basic string up requirement is that the yarn be under tension as it contacts the rotating discs.

The apparatus for practicing the invention will be described in conjunction with FIGURE 4 of the drawing.

Reference number 26 refers, as in FIGURES 1, 2, and 3, to the disc assembly in its entirety. Discs 36 and 38 are connected to shafts 44 which are unidirectionally rotated by an endless belt (not shown) or by other rotating means, such as a gear assembly. The discs are heated by donut heaters 40. The heaters are held in place by heater retainers 42.. Spacer 48 establishes the space in which the discs rotate. The heaters and discs are insulated from the atmosphere by insulation 50. Bolts 46 hold the entire assembly together.

The distance between discs can be from A to & inch. They should, however, be as close as possible.

Because of the difficulty in measuring the temperature of the rotating discs themselves, temperature is measured on the heater retainer. At equilibrium this temperature is almost identical to that of the discs.

The discs can be made of many metals, such as aluminum and brass, however, the best metal is stainless steel, which may be refractory coated if such is desired.

The invention will be further described by the next below example. This example is meant to be illustrative, and is not intended to limit the invention in any way.

EXAMPLE This experiment was performed using the string up shown in FIGURE 1 and will be described with reference thereto. Fifteen denier rnonofilament yarn 1th was supplied from spin cake 12. Feed roll 16 was operated at 67 yards/min. Draw roll 20 speed was 320 yards/min. Discs used in this experiment were knife-edged and were operated at 3360 yards/min, measured at the disc edge. Disc retainer temperature was 2l0 220 C. All other equipment temperature was at 6580 F. Yarn tension was adjusted to almost the breaking point. The yarn scuffed in accordance with the invention under the above described conditions employing the string up shown in FIG. 1 is compared in the table below with yarn not scuffed, but otherwise treated the same.

Luster was measured with a Hunter Lab Model D-l6 Multipurpose Glossmeter. In this instrument reflected light from a sample is measured by two photoelectric cells. One cell is disposed at 45 with respect to a line drawn perpendicular to the sample. The light source is placed at 45 with respect to the same perpendicular line but on the opposite side. The second cell is placed at the same distance from the sample as the first cell. The second cell is placed on the perpendicular line with respect to the sample. The luster of the sample is given in percentage by the following equation:

where L is luster, D is reflected light measured by the photoelectric cell that is disposed perpendicularly with respect to the sample, and S is reflected light measured by the photoelectric cell disposed at 45 with respect to a perpendicular line drawn through the sample.

A stocking made from yarn treated in accordance with this experiment had higher pick-pull resistance, was cooler to the wearer and had fewer runs than the comparable, but untextured, yarn.

It is apparent that the invention offers an improved method for texturing yarn. Yarn produced in accordance with the invention has significantly decreased luster. A fabric produced from yarn treated by the instant invention has improved properties, such as run resistance. The apparatus for practicing the method is simple and almost maintenance free.

The invention has been described with reference to specific drawings and examples. The invention, however, is only limited by the scope of the appended claims.

We claim:

1. A method for texturing continuous filament yarn made from a thermoplastic polymer comprising the steps of:

(a) providing a yarn source;

(b) passing said yarn under tension into contact with the periphery of a plurality of axially parallel, thin, unidirectionally rotating, heated surfaces, said yarn being axially parallel with the rotational axes of said surfaces, thereby deforming said yarn; and

(c) collecting said yarn in an orderly manner.

2. The process of claim 1 wherein the yarn is monofilament nylon.

3. A method for texturing continuous filament yarn made from a thermoplastic polymer comprising the steps of:

. (a) providing a yarn source;

(b) wetting said yarn with a thermoplastic solvent thereby softening said yarn;

(c) passing said softened yarn under tension into contact with the periphery of a plurality of axially parallel, thin, unidirectionally rotating surfaces, said yarn being axially parallel with the rotational axes of said surfaces, thereby deforming said yarn; and

(d) collecting said yarn in an orderly manner.

4. The process of claim 3 wherein the yarn is monofilament nylon.

5. The process of claim 1 wherein the heated surfaces number two.

6. Apparatus for texturing thermoplastic yarn comprising:

(a) a plurality of adjacently spaced, overlapping, unidirectionally rotatable discs whose axes of rotation are substantially parallel;

(b) means operatively connected to said discs for rotating same;

(c) means for heating said discs; and

(d) means surrounding said discs for insulating same from the atmosphere.

'7. Apparatus for texturing thermoplastic yarn comprising:

(a) a pair of adjacently spaced, overlapping, unidirectionally rotatable discs whose axes of rotation are substantially parallel;

(b) a shaft operatively connected to each of said discs;

(c) means for rotating said shafts;

(d) means for heating said discs; and

(e) means for insulating said discs from the atmosphere.

8. The apparatus of claim 7 wherein the edges of said discs are knife-edged.

9. The apparatus of claim 7 wherein the edges of said discs are rounded.

References Cited UNITED STATES PATENTS 2,173,621 9/1939 Campolunghi 19-64 3,140,526 7/1964 Tlamicha 2867 LOUIS K. RIMRODT, Primary Examiner. 

